WASHINGTON — Believing reusable first-stage boosters could make future rockets cheaper to operate and quicker to the launch pad, the U.S. Air Force is initiating multiple efforts to study and demonstrate technologies associated with this long-sought capability.

In contrast to the completely expendable rockets the Air Force relies on today for putting satellites in orbit, the rockets the service envisions for the future would be built around a first stage capable of flying back to the launch site to be refueled and flown again.

The U.S. Air Force Research Laboratory (AFRL) plans to fund a small-scale demonstration of a first-stage booster that can separate and return to the launch site for landing using its own residual rocket power, also known as a rocket-back maneuver. Under the Reusable Booster System Pathfinder program, AFRL intends to award $1.5 million contracts to as many as three companies for initial design studies and test plans, according to an April 5 posting on the Federal Business Opportunities website. AFRL held an industry day in May, during which companies were told to expect a draft request for proposals for the program in August, an industry source said.

Following the study phase, AFRL intends to pick no more than one company to begin a phased development of a small-scale demonstrator, beginning with a ground test of the booster’s propulsion system. The next phase of the program, according to the posting, would include at least two flight tests of the booster, and the final phase would culminate with a rocket-back maneuver and horizontal landing. AFRL intends to spend no more than $28.5 million on the demonstrator, not including the initial study contracts.

The Air Force Space and Missile Systems Center (SMC), meanwhile, has initiated its own investigation of reusable boosters and will solicit proposals from firms to study different aspects of the concept. Several companies may be awarded study contracts totaling $2 million, according to a June 17 posting on the Federal Business Opportunities website. A draft request for proposals is expected in July with awards anticipated in October, it said.

Firms will be asked to study different methods to returning to the launch site for horizontal landing:

  • The booster could redirect itself while still under rocket power and then glide back to the launch site.
  • The booster could use jet engines to propel itself back to the launch site.
  • The booster could rely solely on gravity and its own aerodynamic properties to glide back to the launch site.

The firms also will be asked to study two different methods for booster separation: one in which the upper stage is jettisoned before ignition, and one in which ignition of the upper stage occurs at the time of separation, the posting said.

Firms also will study the feasibility of aborting the launch attempt after liftoff. In a configuration where the first-stage booster and upper-stage boosters are aligned side by side, this would involve the first-stage booster jettisoning the upper-stage motors, but retaining the payload and returning it to the launch site, the posting said.